| US 7,340,010 B2 | ||
| Forward error correction coding for hybrid AM in-band on-channel digital audio broadcasting systems | ||
| Brian William Kroeger, Sykesville, Md. (US) | ||
| Assigned to iBiquity Digital Corporation, Columbia, Md. (US) | ||
| Filed on Jan. 26, 2004, as Appl. No. 10/764,629. | ||
| Prior Publication US 2005/0163256 A1, Jul. 28, 2005 | ||
| Int. Cl. H03C 1/52 (2006.01) | ||
| U.S. Cl. 375—300 [375/265; 375/268; 375/270; 375/320; 375/316; 714/786; 714/792; 714/790; 714/796] | 17 Claims |
| 1. A receiver for receiving an AM compatible digital audio broadcasting signal, the receiver comprising:
an antenna for receiving a composite signal comprising an analog modulated carrier signal centrally positioned in a radio
channel, wherein the analog modulated carrier signal is modulated by an analog signal, and a plurality of digitally modulated
subcarrier signals in the radio channel, wherein the digitally modulated subcarrier signals are modulated using complementary
pattern-mapped trellis code modulation including a code mapped to overlapping partitions; and
means for producing an output in response to the composite signal;
wherein in a first operating mode the analog modulated carrier signal and the plurality of digitally modulated subcarrier
signals are in a 20 kHz channel and the analog modulated signal is delayed with respect to the plurality of digitally modulated
subcarrier sianals, and in a second operating mode the analog modulated carrier signal and the plurality of digitally modulated
subcarrier signals are in a 30 kHz channel and a first group of the plurality of digitally modulated subcarrier signals are
delayed with respect to a second group of the plurality of digitally modulated subcarrier signals.
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